One step in the electrophotographic printing process typically involves a toner supply member of a toner cartridge providing a relatively uniform layer of toner to a developer member. The developer member in turn supplies that toner to a photoconductive element to develop a latent image thereon. The toner layer supplied by the toner supply member to the developer member is often much greater than what is required for quality image formation. A doctor blade “doctors” this layer into an acceptable thickness prior to supply to the photoconductive element.
In an image forming device the toner supply member is typically considered to have two primary functions. The first is to remove undeveloped toner from the developer member. The second is to supply a sufficient and consistent quantity of uniformly charged toner to the developer member surface prior to the doctor blade.
While the surface properties of the developer member and the doctor blade have long been known to be factors in the control of the toner layer on the developer member, it has been discovered that the properties and architecture of the toner supply member are also a factor in controlling the thickness of the toner layer supplied to the developer member.